This invention relates to the field of socket wrenches, and more particularly to a socket wrench having a ratchet head which is ortogonally pivotable with respect to the wrench handle so that the wrench handle may be adjusted at an angle with respect to the surrounding work surface.
The well-known socket wrench is used in all areas of our technological society. However, it is difficult for known wrenches to be used in tight spaces, particularly where surface obstructions are located adjacent to the nut or bolt which is to be driven. It is known to use extension rods which allow the socket wrench to be vertically displaced above the working surface so as to avoid the aforementioned surface obstructions. However, such extension rods are subject to breaking and are themselves limited by the space available in the vicinity of the nut or bolt to be driven. Therefore, it would appear to be advantageous to provide a socket wrench in which the ratchet head is made pivotable with respect to the wrench handle so that the ratchet head may be coupled to the nut or bolt while the wrench handle is vertically displaced from the working surface upon which the nut or bolt is mounted.
Such a wrench was proposed in U.S. Pat. No. 1,320,137 to Gunn. Gunn provides a wrench handle with a yoke extending from one end thereof. The ratchet head includes two trunions which are mounted on opposite sides of the yoke so that the ratchet head is pivotable with respect to the wrench handle. A disadvantage of the wrench according to Gunn is that the yoke does not totally encompass the ratchet head. Thus, when great force is applied to the wrench handle, the yoke is subject to bending and/or breaking due to its structural infirmity. Another disadvantage of the wrench according to Gunn is that the trunions sometimes shear off or are deformed when great force is applied to the wrench handle.
A further disadvantage of the Gunn wrench is that the wrench handle may be pivoted entirely around the ratchet head. Those having skill in the wrench-design field will recognize that once the Gunn wrench handle is pivoted greater than 45.degree. with respect to the working surface, the wrench handle must be twisted with a torque-like action rather than being pushed in a direction perpendicular to the wrench handle. In such circumstances, the mechanical advantage of the wrench is greatly reduced.
A further disadvantage of the wrench according to Gunn is that no means are provided to temporarily fix the angle between the wrench handle and the ratchet head. Applying face to the handle may cause it to pivot entirely over the top of the ratchet head and lose mechanical advantage. Thus, a person using the Gunn wrench may find it extremely difficult to operate since the handle is freely pivotable with respect to the ratchet head. Thus, Gunn provides no temporary fixing means by which the angle between the wrench handle and the ratchet head may be temporarily fixed at the most advantageous position.
Another wrench with a pivotable ratchet head was proposed in U.S. Pat. No. 2,977,824 to Rueb. In Rueb, the ratchet handle is a split handle with a yoke-like portion extending on each side of the split. The ratchet head is mounted by trunions to each of the yoke-like portions. Like Gunn, the Rueb wrench is subject to bending at the yoke-like portions and shearing off or breaking the trunions. Also, Rueb provides no means for limiting the pivot angle of the ratchet head with respect to the handle, nor temporary fixing means by which the pivot angle may be temporarily fixed at a desired angle.
Another wrench with a pivotable handle was proposed in U.S. Pat. No. 3,186,265 to Wenturine et al. However, the Wenturine wrench pivots the handle with respect to the ratchet housing and thus, the pivot axis does not pass through the ratchet head. Such an arrangement reduces the mechanical advantage which can be obtained by providing the pivot axis through the ratchet head. Like the Gunn and Rueb devices, the Wenturine wrench pivots about a pin (trunions) which is subject to shearing under great load.
Therefore, there is a need for an orthogonally adjustable socket wrench in which the ratchet head is pivotable with respect to the wrench handle, and wherein the structure will not be easily broken or damaged by the application of great force to the wrench handle. In addition, such a wrench should provide stopping means by which the angle between the ratchet head and the wrench handle may be prevented from exceeding 45.degree.. Also, such a wrench should provide means for temporarily fixing the angle between the ratchet head the wrench handle at a desired operating angle.